Before printed products are in their finished state, they can be processed by numerous different machines. Thus, following the rotary machine, newspapers pass through different working stations, e.g. an insertion device, an addressing station or a packing station. The printed products are normally conveyed between the individual machines in the form of a scale flow. Nowadays such conveying is more particularly carried out by conveyor belts or revolving chains with clamping elements operatively connected thereto.
In known installations, a conveyor belt linearly conveys in the forward direction and generally at a uniform speed the scale flow located thereon. It is only possible to overcome very slight up and down gradients unless use is made of special pressing means. Special conveying means must be located between the conveyor belts for curves. Although several conveyor belts can be joined together to form longer paths, the conveyed items must be large enough to be able to be pushed from one belt whilst they are still adequately supported on the next belt to permit further conveying thereof. However, as the scale flow often rests loosely on the conveyor belt, the individual scales can be reciprocally displaced in the conveying direction for a number of reasons and this can lead to irregularities in the scale flow and in certain circumstances to errors in the operating steps following conveying.
Chains with clamping elements operate in the same way as conveyor belts. However, as the scale flow or the individual elements thereof are secured by the clamping elements, it is possible to overcome up and down gradients, as well as curves. Conveyor systems comprising chains with clamping elements must be "tailor-made" for each particular application, because they cannot be assembled in a simple modular manner. A special transfer station is required between two conveying modules comprising chains with clamping elements.
Conveying with conveyor belts and conveyor systems with chains and clamping elements are restricted in that the scale flow must move uniformly over the entire conveying path comprising one or more conveyors. Thus, even in the case of slow conveying, it is not possible to insert even minor working steps for which it would be necessary to stop individual or several pieces for even a short time, without periodically stopping the entire conveyor belt or the complete series of conveyor belts. Conveyor belts and conveyor systems with rotary chains and clamping elements require a large amount of space for the unused return strand or side and in most cases have high construction cost.